High-Performance Class AB Amplifier Design. For electronics enthusiasts and professionals who want to build high-power sound systems, the MATRIX 1.4-DOS-V amplifier circuit is a highly successful and field-proven power amplifier design.
This circuit, especially used in active stage sound reinforcement systems, has high output power and stable operating characteristics.
The output stage transistors used in this project are MJ15003 / MJ15004, and 2SC3858 / 2SA1494 can be preferred as alternatives. KiCad schematic and PCB project files of the circuit are available.
In addition, a speaker protection circuit is also included in the design; however, only the schematic drawing is available for this section, and there is no PCB layout file.
General Features of the Amplifier
Contents
MATRIX 1.4-DOS-V is a Class AB audio power amplifier with dynamic output power reduction. Its ability to operate especially with low-impedance speakers makes it ideal for professional use.
Technical Specifications
- Maximum Peak Output Power: 1000 Watt (at 2 Ohm load)
- RMS Output Power: 500 Watt RMS @ 2 Ohm
- Bridge Mode RMS Power: 1000 Watt RMS @ 4 Ohm
- RMS Output Voltage: 31.6V RMS
- Peak Output Voltage: 44.7V Peak
- Frequency Response: 20Hz – 20kHz
- Maximum Gain: 33 dB
- Input Sensitivity: 707 mV Peak
- Supply Voltage: ±63V DC symmetric power supply
MATRIX 1.4-DOS-V Amplifier Field Tests
MATRIX 1.4-DOS-V Amplifier NGSPICE Simulator Tests
These values show that the circuit can operate over a wide frequency range and keeps distortion low by providing high headroom.
Prominent Advantages of the Circuit Design
High Power Capacity
Thanks to its ability to operate with a 2 Ohm load, it offers high performance especially in large PA systems and subwoofer applications.
Stable Class AB Structure
The Class AB topology combines the low-distortion advantage of Class A with the high efficiency of Class B.
Dynamic Power Reduction System
The DOS-V feature protects both the speaker and the amplifier by reducing the output power in a controlled manner under overload conditions.
Powerful Transistor Stage
MJ15003 / MJ15004 transistors are preferred in professional applications due to their high current capacity and thermal durability.
Installation Instructions
To operate this amplifier without problems, the following technical rules must be observed:
All resistors whose power is not specified in the schematic should be selected as 0.25W.
Arbitrary changes should not be made to the circuit schematic.
The supply voltage is ±63V DC, and approximately 10% tolerance is acceptable.
The differentially operating transistor hfe pairs must be of the same model and brand.
The power supply transformer must have a 2x47V AC output.
The number of power transistors in the output stage must absolutely not be reduced.
Signal and power grounds must be kept separate (S.GND / P.GND).
In dual-channel use, ground connections must be made correctly.
Coil winding: 22 turns, 0.9 mm wire, approximately 0.35 inch radius.
Compliance with these rules is critical for the amplifier in terms of stability, noise level, and long service life.
This amplifier design is a very suitable solution especially for: those building professional sound systems, those who want to build a high-power subwoofer amplifier, electronics enthusiasts interested in DIY audio projects, and those designing stage sound reinforcement equipment.
The MATRIX 1.4-DOS-V amplifier circuit is an excellent option for those looking for a powerful DIY amplifier project with high power capacity, reliable operation, and professional-use features.
When used with correct assembly and a suitable power supply, a robust audio amplifier that can operate without problems for many years can be obtained.
source: sourceforge.net/projects/matrix14freeamp (closed)
